Named for Philip A. Davis, planetary geologist with the U.S. Geological Survey and chief of the Branch of Astrogeology since 1989. Davis has worked on the global geochemistry and petrology of the moon and the geology of Mars, Venus and Arabia. He is known especially for the techniques he has developed for the extraction of quantitative topographic information from spacecraft images and for analysing global patterns of geological and geophysical data. (M 17657) _ _.